Location: Cotton Structure and Quality ResearchTitle: Chromophores in cellulosics, VI. First isolation and identification of residual chromophores from aged cotton linters Author
|Peralta-inga Shields, Zenaida|
|French, Alfred - Al|
Submitted to: Cellulose
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/17/2011
Publication Date: 11/11/2011
Citation: Rosenau, T., Pothast, A., Krainz, K., Yoneda, Y., Dietz, T., Peralta-Inga Shields, Z., French, A.D. 2011. Chromophores in cellulosics, VI. First isolation and identification of residual chromophores from aged cotton linters. Cellulose. 18:1623-1633. Interpretive Summary: Materials such as cotton fibers and paper turn yellow with age. This yellowing is accompanied by degraded performance, and decreased economic value. The fundamental research in this paper extracts and identifies the molecules that cause the color to occur despite very low amounts. Further, the research indicates that the molecules in question (chromophores) come from the cellulose molecule, the main component of cotton and paper. Previously there was strong opinion that they might arise from other molecules that are present in cellulose derived from wood. This work, conducted with cotton linters, does not have those other molecules, leaving products of reactions with cellulose as the most likely culprit.
Technical Abstract: In the present work, aged cotton linters have been analyzed for their chromophore content according to the CRI (“chromophore release & identification”) method. Despite the very low contents in the ppb range, nine chromophores have been unambiguously identified, which makes this account the first one on defined chromophoric structures isolated from cotton. A common feature of the chromophores are 2-hydroxy-[1,4]benzoquinone, 2-hydroxyacetophenone and 5,8-dihydroxynaphthoquinone moieties, which resemble chromophoric structures found in other cellulosic substrates, such as bleached pulps or fibers. The finding of these compounds in lignin-free cotton linters confirms the previous hypothesis that those chromophores are formed from (oxidized) carbohydrate structures rather than from lignin fragments.